DAYTONA BEACH, Fla. — The story of the Grand Touring Prototype class championship in the 2025 IMSA WeatherTech SportsCar Championship is a tale of two halves.
The No. 7 Porsche Penske Motorsport Porsche 963 and drivers Felipe Nasr and Nick Tandy won the first three races of the nine-race slate to take what looked like a comfortable lead over their teammates Matt Campbell and Mathieu Jaminet in the No. 6 Porsche, with BMW M Team RLL – especially Dries Vanthoor and Philipp Eng in the No. 24 BMW M Hybrid V8 – shaping up as their strongest competition.
But Porsche went winless in the final five rounds of the title chase following Jaminet and Campbell’s triumph at the TireRack.com Monterey SportsCar Championship at WeatherTech Raceway Laguna Seca in May.
Meanwhile, Acura Meyer Shank Racing w/Curb-Agajanian and Cadillac came to the fore – especially the No. 31 Cadillac Whelen Cadillac V-Series.R driven by Jack Aitken and (with one exception) Earl Bamber, which closed out the campaign with a pair of wins in the TireRack.com Battle On The Bricks at Indianapolis Motor Speedway and the Motul Petit Le Mans at Michelin Raceway Road Atlanta. That vaulted Aitken all the way up to second place in the final driver standings.
Ultimately, it was the consistency of Campbell and Jaminet and the No. 6 Porsche that propelled them to the GTP driver’s title while also helping Porsche hold off Acura for the IMSA Manufacturer’s Championship. Both 30 years old, Frenchman Jaminet and Australian Campbell are successful products of Porsche’s worldwide Junior program. They teamed together at Pfaff Motorsports in 2022 in a Porsche 911 GT3 R to win five of 10 races on the way to IMSA’s first Grand Touring Daytona Pro (GTD PRO) class championship.
Jaminet and Campbell were promoted to Porsche Penske Motorsport’s GTP effort in 2023 but assigned to different cars. Reunited in 2025, they added five podiums to their victory at Laguna Seca and never finished lower than seventh. Most importantly, they completed the season virtually mistake-free.
“Phenomenal to get another championship with Mathieu – that’s two years in IMSA partnering together and two championships, so very proud of that,” Campbell said. “For sure, it wasn’t the whole year we wanted. From the start of the year, we were lacking a little bit behind the No. 7, but I think it really showed our consistency and our drive together that put us in this position for the championship title. A very special day I won’t forget.”
Added Jaminet: “The start of the year was a little bit frustrating, but I always knew we had a championship shot. It was about staying on track, not making mistakes, and it’s going to come our way. This is exactly what happened. We supported each other, even on bad days. It worked out pretty well and I cannot be more happy than today, that’s for sure.”
The winning championship margin between the No. 6 Porsche and the No. 31 Cadillac was 188 points.
After Nasr and Tandy finished second to their Penske Porsche Motorsport teammates at Laguna Seca, the No. 7 Porsche had a 91-point advantage over the No. 6. The No. 24 BMW was 280 points back and the No. 31 Cadillac was fifth in the standings, trailing by 368 points.
Nasr led 31 laps at the Chevrolet Detroit Grand Prix but finished fourth right behind the No. 6, as cars on fresher tires powered through in the closing stages. Nick Yelloly and Renger van der Zande took the win in the No. 93 Acura, the first for the MSR entry that features race engineering support from Honda Racing Corporation USA (HRC US) associates.
That fourth-place finish represented the last bright spot of the season for the No. 7 Porsche. Tandy crashed heavily in the closing stages of the Sahlen’s Six Hours of The Glen at Watkins Glen International, a race won by the No. 60 Acura with drivers Tom Blonqvist and Colin Braun. At Road America, Tandy incurred a stop and 60-second hold penalty for incident responsibility; the No. 7 received two drive-throughs for lesser offenses at Indianapolis. Tandy and Nasr never finished higher than 10th in any of the final four races and slipped to third in the driver’s standings behind Aitken.
Dries Vanthoor emerged as a star as he sped to the Motul Pole Award in the first four races of the season. But BMW was unable to translate the single-lap speed they showed in the first four races of the year, struggling with consistency and correct strategy. Eng and Vanthoor finally broke through to take a convincing win (with Sheldon van der Linde and Marco Wittmann completing a BMW 1-2 in BMW M Team RLL’s No. 25 BMW M Hybrid V8) at the Motul SportsCar Grand Prix at Road America. They were on pace to take second in the driver’s championship until Eng dropped from fourth to ninth place with a punctured tire with just 10 minutes remaining in the Petit Le Mans finale, relegating them to fourth. Second through seventh final in the standings were separated by just 118 points.
While Aitken, Bamber and Frederik Vesti won the final two races in the No. 31 Whelen Cadillac, Wayne Taylor Racing endured a challenging winless season in their reunion campaign with the General Motors marque. The highlight came at Watkins Glen, where WTR put two top-class cars on the podium for the first time in its long history. The No. 10 Cadillac duo of Filipe Albuquerque and Ricky Taylor scored the third-highest point total in the last five races to end the year fifth in the standings, four places ahead of teammates Jordan Taylor and Louis Deletraz in the No. 40 V-Series.R.
The No. 85 JDC Miller MotorSports Porsche 963 was the only private entry to contest the full GTP championship in 2025, with the yellow car’s season highlighted by a sixth-place finish in the Rolex 24 at Daytona International Speedway. The No. 23 Aston Martin Valkyrie joined the fray at the Mobil 1 Twelve Hours of Sebring and showed increasing pace throughout the rest of the year, culminating in a popular second-place finish for Roman De Angelis, Ross Gunn, and Alex Riberas at Petit Le Mans. The No. 63 Automobili Squadra Corse Lamborghini SC63 also had its most competitive outing to date at Michelin Raceway Road Atlanta, with Romain Grosjean, Edoardo Montara, and Daniil Kyvat claiming fourth at the flag.
Acura closed the gap to Porsche in the Manufacturer’s Championship to just two points following Blomqvist’s pole in Petit Le Mans qualifying, but a fifth-place finish for Blomqvist, Braun, and Scott Dixon in the No. 60 was not enough to overcome champions Campbell, Jaminet, and Laurens Vanthoor’s run to third.
“We may have finished second, but we showed up and we fought hard every weekend, and we can hold our heads high for the effort,” said HRC US President David Salters. “I’m immensely proud of everyone here.”
